The invention relates to a laying rail for series shed weaving machines and to a laying-in apparatus with laying rails.
A laying rail for laying warp threads into the weaving rotor of a series shed weaving machine is known from published European patent application EP 0 612 875 A1. This laying rail is movably mounted in the direction of extent of the weaving rotor and has a large number of cut-outs, with each warp thread extending through a cut-out and being guided thereby. The warp threads can thus be positioned with respect to the weaving rotor, i.e., to its shed forming members, through a corresponding moving of the laying rail.
A disadvantage of the known laying rail is that warp thread breakages can arise in the case of a larger thickened region in the warp thread or in the event of knots.
It is an object of the present invention to propose an economically more advantageous laying rail and a laying-in apparatus which is matched to it.
The object is satisfied by a laying rail for a series shed weaving machine, comprising a plurality of cut-outs for guiding warp threads, with each cut-out comprising two end sections and a guide section which lies between them, and with the cut-out having a greater width in the region of the two end sections than at the guide section.
As a result of the relatively wide end section of the cut-outs, the laying rail of the present invention has the advantage that a thick point in the warp thread, for example a knot, can slide relatively unhindered through the wide end section, so that no excessive forces act on the warp thread as a result of this thick point. The second wide end section of the cut-out serves for threading the warp thread into the laying rail. During normal operation the warp threads pass through the guide section which is arranged between the two end sections. This guide section has a relatively small gap width, so that the warp thread which is guided therein can be positioned very precisely through the transverse movement of the laying rail. Thus the warp threads can be very precisely laid into the shed holder means which are arranged on the weaving rotor. An essential advantage of the laying rail in accordance with the invention is also to be seen in that the warp threads can also be laid into shed holder means which have a small mutual spacing. Thus the manufacture of a cloth with a high warp thread density is possible.
The laying-in apparatus, which is designed to be matched to the laying rail, has in a preferred embodiment a separate deflection element for the warp threads. The laying rails and the deflection elements for the warp threads which are to be supplied to the laying rail are supported in a common holder, but are supported with a spatial separation from one another. The laying rails are axially movably mounted in guide supports which are formed on the holder, and the deflection elements are stationarily mounted in separate cut-outs of the holder. The deflection elements are in each case arranged above and below each group of warp threads and are manufactured of preferably low wear material or ceramics. Through this design of the laying-in apparatus, i.e. in particular as a result of the separate guide supports for the laying rails, a transfer of the heat which arises through the friction of the warp threads on the deflection elements can be kept away from the laying rails to the greatest extent. Temperature-induced length changes of the laying rails can thereby be avoided, which enables a precise holding and guiding of the warp threads by means of these laying rails. The position of the warp threads is precisely reproducible, which in turn enables the manufacture of a cloth with high warp thread density.